The monitoring of areas for various purposes, such as traffic control, animal or human intrusion deterrence, and/or surveillance for security or other purposes, has become increasingly important with population increases and the pressures of a more complex society. Such concerns are often apparent to the observer, who may readily note remote camera installations and security guards and personnel in banks, shopping malls and other areas, as well as pneumatic or other traffic monitoring devices on the road. Such devices and services can be relatively costly, particularly in the case of monitoring or security personnel. However, in some situations there have been no suitable alternatives to such personnel due to the relatively high power demands of many security systems, such as floodlighting for camera surveillance, etc., as well as the need for human observation.
The need arises for a surveillance system which is capable of operating upon demand, i.e., when an intruder or intruders approach the area covered by the system. The system should require relatively low power in normal use, as the additional power required for lights, audio devices, cameras, etc. need only be supplied when required by the primary sensing means. The primary sensing means should be of a passive nature, which renders such sensing means more difficult to detect, as well as further reducing power demands and costs. The system should respond to the needs of surveillance security, by providing a relatively high resolution, narrow field of view video of any intruder in the area, by means of a secondary range determination system providing input to a camera control for elevation and control of the focal length thereof. Moreover, the system should be relatively inexpensive to manufacture and operate in comparison to other systems developed.